In the heart of the jungles of central America is one of the most important sites of the Mayan civilization-the Tikal, Tikai was once the largest city in the Mayan world, Experts think 90,000 people used to We here However, by AD, 950, all the people had left the city. Then the rain forests returned to completely cover the land. Today, historians and tourists can visit Tikal and see some of the 3.000 ancient structures that once stood there. Among the ruins are six huge pyramids. Some are more than 60 meters(200 feet high. On tese pyramids are carved pictures. They help us understand what the Maya were like and how they lived. The ruins of Tikal also give us important clues to solve the mystery of why they left and never returned. Experts believe there were a few reasons the Maya left Tikal. It didn't rain very often, so there was not enough water to drink or to grow food. Also, Tikal was always at war with other cities, and some people may have left to avoid the war Today, in addition to its important ruins, Tikal National Park contains the largest area of wild rain forest in Central America It protects thousands of unique plant and animal species.